Electrolytic cell



Dec. 29, 1931. R. ROBERTSON ELECTROLYTIC CELL Filed June 13, 1929 74-4) 8R0: new.

Patented Dec. 29, 1931 REUBEN B. ROBERTSON,

0F ASHEVILLE, NORTH GARQLINA, ASSIGNOR TU THE CHAMPION FIBRE COMPANY, OF CANTON, NORTH CARQLINA, A CURPORATIQN 0F @HJEU Application filed June 13,

This invention relates to apparatus adapted for use in the electrolysis of various electrolytes, .such as saline solutions, and more particularly is concerned with an electrolytlccell for the electrolytic decomposition of a sodium chloride electrolyte. v

An object of the invention is to provide an electrolytic cell which is compact in form, simple in construction, sturdy in structure, and eficient'in operation. Other objects of invention will appear hereinafter.

My invention, in essence, resides in the provision of a electrolytic cell comprising an impervious,vpreferably, substantially cylindricaL-base, two endless cathodes of foraminous structure throughout their active portions supported thereupon, one within another, the cathodes themselves carrying on their adjacent surfaces suitable diaphragms, the cathodes with the base forming an endless, preferably annular,anode chamber, and an anode or anodes within said chamber. The cathodes are vertically disposed, are spaced in parallel relationship to each other, and preferably are substantially cylindrical and so arranged upon the base that their longitudinal axes are coincident.

At points near their upper edges the oathodes are provided with, laterally extending flanges upon which is supported a cover between whose marginal edges there is provided a chamber which extends above the cathodes and above the normal level of the electrolyte within the anode chamber, forming a gas dome over said electrolyte. :The anodeforming means is suspended, within sa1d anode chamber, from said cover.

At the bottom of the outer and the inner cathodes, respectively, ll provide separate means for the reception of liquids,i. e., for the reception of caustic alkali solution which means is carried by the base.

The invention will be described with greater particularity in the following description of an illustrative embodiment of the inven- JELJEC'EROLYTIG GELL 1929. Serial' No. 370,655

tion and by reference to the aompanying drawings, in which: 1

Fig. 1 is a top plan View ofa preferred form of cell embodying the invention; and

Fig. 2 is a central vertical section, with certain elements shown in elevation, of the cell shown in Fig. 1.

*lleferring now by characters of reference to the drawings: 1 designates an impervious base, preferably of concrete, 2 represents the outer cathode, and 3 the inner cathode, which are supported by the base 1. The cathodes 2 and 3 with the base 1 form an endless anode chamber 4 for the reception of electrolyte, within which chamber are suspended the anodes 5 from the cover 6, which cover is borne above the cathodes 2 and 3 by ring flanges 'Z and 8 bolted or otherwise secured to cathodes 2 and 3, respectively, at their upper ends. Upon the cover 6 rests 9. 10 represents the anodic current COIUHQC'? tion provided on anode ring 9, and 11 represents the cathodic current connection provided on cathodes 2 and 3.

" Tn constructing the cell, I preferably preform the base 1 by casting the same in concrete or other equivalent material, providing thereon and integrally uniting therewith the annular drain trough 12. I also provide in said base the brine inlet whose outer end 14- is in the form of a threaded pipe for connection to a brine feed line (not shown), and as well an opening. 15. The endless cathode 2, which, throughout its active portion, is foraminous by reason ofthe multitudinous apertures therein,

as indicated in Fig. 2, has arranged upon its inner surface a suitable diaphragrn 16, which may be and preferably does consist of sheet asbestos, and, so fabricated, is positioned on the base 1. Preferably, it is made to slip down over the upper edge of the base 1 and to rest upon the annular drip-- trough 12. The cathode 2 with diaphragm then may be bound to the base 1 by means of the tie rodl'l.

the anode ring The inner cathode 3 is fabricated in the form of a basket or drum having a base plate 18, imperforate except for the threaded nipple 19, and the foraminous walls before referred to. I fix a suitable diaphragm 21 of sheet asbestos upon the outer surface of the foraminous walls of cathode 2, and position the oathode upon the base 1, with the threaded nipple 19 extending through the opening 15. Thereafter, a threaded collar 20 is run onto nipple 19, and brought up against the base 1.

The cover 6, which may be and preferably is formed of concrete or like material, is in cross-section shaped in the form of an inverted C whose edges are supported by the cathode flanges 7 and 8 and sealed thereto, as with putty, bitumen, or other suitable material. 22 represents a gas vent in the cover 6. As has been indicated hereinbefore, a plurality of anodes 5 are supported by said cover, by means of suitable lugs 23, 24 represents a gauge glass in cover 6 for indication of the level of electrolyte in chamber 4. I

I may support from cover 6, and somewhat above the normal level of electrolyte in chamber 4, a brine feed cup 25 which may have two bottom outlets for connection, by means of feed lines (not shown), to the threaded pipes 14 of the brine inlets 13 of as many cells.

Although I may use, as the anode-forming means, a unitary annular anode, I prefer for obvious mechanical reasons to provide a plurality of standard anodes,preferably, of graphite,of substantially square or rectangular cross-section through their active portions. Such anodes present two opposite faces which are substantially parallel to the adjacent surfaces of the cathodes. They (the anodes) preferably are of such length as to reach nearly to the bottom of anode chamber 4, and preferably are of such cross-sectional dimensions with respect to the width of the anode chamber as to leave between any outwardly-turned anode face and the adjacent cathode surface a space of suitable workinghwidth,e. g., a distance of about 0.375 inc In operation the electrolyte, which, for the production of caustic soda solution and chlorine as, is a saturated brine (e. g., saturated solution of common salt), is fed into the anode chamber 4, as by means of brine feed cup 25, feed line (not shown) and brine inlet 13, until a suitable body thereof is present in the anode chamber, and a suitable electric current (e. g., of about 3 to 4 volts and about 2000 amperes) is passed therethrough from the anodes to the two cathodes. The electrolyte, held in the anode chamber 4 by means of the diaphragms 16 and 21, is decomposed in known manner, chlorine gas being emitted at the anodes and collecting in the space within cover 6 from which it is passed caustic soda solution percolating through the diaphragms 16 and 21, passing through the apertures of the cathodes 2 and 3, and running down the faces of the said cathodes to drain trough 12 and base plate 18, respectively, from which two sources caustic soda solution is withdrawn to suitable storage (not shown).

Among the chief characteristics of my electrolytic cell are the following:

(1) It is markedly simple in construction.

(2) The cell may be dis-assembled, new diaphragms and/or anodes substituted for old, and the cell re-assembled with a minimum of expense.

(3) The cathodes support the other elements of the cell.

(4) The cell is of large capacity with relation to the amount of floor space occupied by it.

It is noted that, in the preferred embodiment of my invention, there is no provision made for collection of the hydrogen gas which is generated by the electrolytic decomposition of the brine. It is obvious, however, that I may, without departing from my invention, provide an independent casing about the cell, whereby to trap the evolved hydrogen in known manner.

It is obvious, also, that various other changes may be made in the device without departing from the scope of my invention, which scope is defined by the appended claims rather than by the foregoing description and illustrative preferred embodiment.

I claim:

1. An electrolytic cell structure comprising a non-conducting base, a substantially cylindrical foraminous cathode supported on said base, means carried by said base and inside and at the bottom of said cathode for the collection and withdrawal of liquid, an outer foraminous cathode surrounding the first named cathode and supported on said base and forming with the base and the wall of the first named cathode an electrolyte chamber, means supported by said base for collecting liquid at the bottom of said outer cathode, and diaphragms on the adjacent faces of the first named cathode and said outer cathode.

'2. In an electrolytic cell, an impervious non-conducting base, two endless foraminous cathodes supported thereupon above the bottom of said base and arranged one within another and forming with the base a substantially annular anode chamber, a cover for the top of the latter defining a gas dome, said cover being supported by said cathodes, an electrolyte inlet provided for the anode chamber, a gas outlet in said cover, and at least one anode within said chamber.

3. In an electrolytic cell, an impervious non-conducting base, two vertically disposed 55 to suitable storage (not shown), and the endless diaphragm-carrying cathodes sup- 1.31

ported thereupon above the bottom of said ase and with their foraminous portions arranged in parallel spaced relationship to each passing through the inlet provided for 

